Easing functions are typed as methods, so passing them trips @typescript-eslint/unbound-method #59941

Description

Libraries/Animated/Easing.js declares linear, ease, cubic etc. with method shorthand, so types_generated/Libraries/Animated/Easing.d.ts emits cubic(t: number): number;. None of them reads this, and the documented usage passes them unbound (easing: Easing.cubic), which fails typescript-eslint's recommendedTypeChecked (@typescript-eslint/unbound-method).

Fix: declare them as arrow-function properties, so the types become cubic: (t: number) => number.

Steps to reproduce

1. Clone the reproducer gist.
2. npm install --ignore-scripts
3. npx eslint index.ts

React Native Version

0.88.1

Affected Platforms

Other (type definitions)

Output of npx @react-native-community/cli info

Not applicable: type definitions only, no app.

Stacktrace or Logs

4:46  error  A method that is not declared with `this: void` may cause unintentional scoping of `this` when separated from its object  @typescript-eslint/unbound-method

MANDATORY Reproducer

https://gist.github.com/dkarlovi/4c0a3edcec5fab42be4aec8eb6ff1d80

Screenshots and Videos

No response